Access control devices arranged to control access to specific areas has been around for some time. These access control devices may for instance be card readers, readers of biometric data, keypads, tag readers, audio capturing devices, video capturing devices, etc. Door stations enabling a visitor to contact a person in order to gain access to the area are usually mounted at entrances in office buildings, apartment buildings, condominiums, airports, campuses, logistic centres. In some applications one or a few door stations are connectable to a plurality of access granting indoor stations, e.g. one in each apartment. In other applications an access control centre is arranged to handle all or most access requests from a plurality of door stations. A door station may combine many features of the above mentioned access control devices. However, one important feature is to enable communication with a person enabled to allow access to the area. Early door stations included an audio capturing device and a speaker for voice communication with a person authorized to open the entrance. However, nowadays the door stations commonly include a video camera as well. The imagery from the video camera allows the person enabled to allow access to see the person requesting entrance.
Traditionally an access control device like a door station is included in an intercom system, see an example in FIG. 1. In this traditional intercom a plurality of system specific indoor units 102, e.g. in the form of system specific video phones or telephones, are connected to a specialized intercom server 104. A system specific door station 106 is also connected to the intercom server 104 and to a lock mechanism 108 of a door 110. Moreover, the intercom system may include a control desk 112 enabling communication and control of the devices in the system. A person requesting entry via the door 110 connected to the door station 106 either presses a request button on the door station or inputs a request address via some input means on the door station. The request is then sent either to one or a plurality of predetermined indoor units and/or the control desk, in case of the request button being used, or to an indoor unit or the control desk being directly addressed by the user inputting a request address. At the indoor unit or the control desk a user or an operator may view the imagery captured by the door station and/or communicate verbally with the person at the door station and, if they find it appropriate, signal to the door station that the door should be unlocked and/or opened. One drawback with these traditional systems is that they require system specific indoor units, door stations, etc.
More and more systems including door stations for requesting access to areas are designed to enable use of general computers or smartphones running specific applications as indoor units or control desks for authorizing access to an area. However, these systems require the indoor unit or control desk to run an application and therefore these systems are restricted to use devices having specific operating systems.